A rock relief or rock-cut relief is a relief sculpture carved on solid or "living rock" such as a cliff, rather than a detached piece of stone. They are a category of rock art, and sometimes found as part of, or in conjunction with, rock-cut architecture. However, they tend to be omitted in most works on rock art, which concentrate on engravings and paintings by prehistoric peoples. A few such works exploit the natural contours of the rock and use them to define an image, but they do not amount to man-made reliefs. Rock reliefs have been made in many cultures throughout human history, and were especially important in the art of the ancient Near East. Rock reliefs are generally fairly large, as they need to be in order to have an impact in the open air. Most of those discussed here have figures that are over life-size, and in many the figures are multiples of life-size.
Stylistically they normally relate to other types of sculpture from the culture and period concerned, and except for Hittite and Persian examples they are generally discussed as part of that wider subject. Reliefs on near-vertical surfaces are most common, but reliefs on essentially horizontal surfaces are also found. The term typically excludes relief carvings inside caves, whether natural or themselves man-made, which are especially found in Indian rock-cut architecture. Natural rock formations made into statues or other sculpture in the round, most famously at the Great Sphinx of Giza, are also usually excluded. Reliefs on large boulders left in their natural location, like the Hittite İmamkullu relief, are likely to be included, but smaller boulders may be called stelae or carved orthostats. Many or most ancient reliefs were probably originally painted, over a layer of plaster; in some traces of this remain.
